Integrated air-borne towing apparatus



June 30, 1959 R. P. BALDWIN ET AL 2,392,599

INTEGRATED AIRBORNE TOWING APPARATUS 3 Sheets-Sheet 1 Filed June 14, 1957 INVENTORS 05567 R 54am wm c2 r06 5. df/v/V/lvs BY ,8 wan/v0 {CA/87 June 30, 1 R. P. BALDWIN ET AL 2,

INTEGRATED AIR-BORNE TOWING APPARATUS 3 Sheets-Sheet 2 Filed 'June 14, 1957 June 30, 1959 R. P. BALDWIN ET AL 2,892,599

INTEGRATED AIR-BORNE TOWING APPARATUS 5 Sheets-Sheet 3 Filed June 14, 1957 lNV NTORS 8085 87 R BELOW/M a H H. M D

United States Patent INTEGRATED AIR-BORNE TOWING APPARATUS Robert P. Baldwin, Clyde S. Jennings, and Raymond H. Eckert, Yuma, Ariz.

Application June 14, 1957, Serial No. 665,870

7 Claims. (Ci. 244-3) (Granted under Title 35, U.S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to us of any royalty thereon.

The present invention relates to an improved towing apparatus for high speed towing operations; and more particularly relates to an integrated, high performance air-borne towing apparatus attachable to an aircraft for the purpose of launching and recovering a lightweight, shaped high speed tow target.

, The present invention is concerned with the provision of a highly simplified, yet powerful and efiicient tow target system for high speed towing operations. The above is accomplished in a unique manner by the present invention which makes possible the elimination of reduc, tion gearing between the turbine and Windlass unit in a towing system, achieves utmost utilization of the force of the air stream, and at the same time streamlines the entire tow target system against the drag effects of the slip stream. Furthermore, a target launching and recovery compartment is integrally joined with the main Windlass and turbine unit so as to provide a compact, lightweight and integrated towing apparatus.

A primary feature of this invention is directed to the utilization of an air actuated drive means which is mounted and designed in such a way as to provide sufiicient power for the direct driving of a Windlass and cable towline. For furnishing maximum power from the air stream for operation of the turbine and Windlass unit, an air inlet and valve means are provided which not only effect the increased flow of air for driving the turbine but also forms a streamlined forward nose portion for the entire tow target system during flight operations to considerably reduce the drag on the aircraft.

Another feature of this invention is directed to the mounting, relative disposition and construction of the Windlass unit including a level wind mechanism driven by the Windlass unit for the level winding and unwinding of the tow cable line. The Windlass unit is constructed so that friction and binding due to rotation in travel of the Windlass and level Wind mechanism are substantially reduced so as to lower the amount of power required for operation of the Windlass. Also, a simplified brake mechanism is provided to increase the efiiciency and response of the Windlass unit during winding operations, the brake means being compactly mounted in such a way as to insure air cooled operation free of failure due to seizure and slippage of the brakes.

An added feature of the present invention is directed to a tow target launcher and recovery assembly which is incorporated into the tow target system so as to operate in unison with the main Windlass and turbine unit. The launcher and recovery assembly provides means for initial launching of a target and buffer means to recover the target upon termination of towing operations. The launcher assembly is also vented in such a way as to impose the force of the air stream onto the target to aid in the launching operation, to decrease drag during tow-j ing and to increase target stability during the last phase of the target recovery operation.

In accordance with the foregoing advantages and features as set forth, it is therefore a primary object of the present invention to provide for a' direct drive, streamlined tow target unit conformable for attachment and operation on the majority of towing vehicles for the launching and recovery of towing members at high speeds.

It is another object to provide for a compact, light-' weight and integrated Windlass mechanism for the guiding and controlling of a cable towline for the operation and release of a high speed, shaped tow target.

It is a further object to provide for an integrated towtarget system incorporating a ducted direct drive turbine together with a launching and recovery assembly for the release and retrieval of a high speed, shaped tow target.

The above features and advantages of the present invention, together with additional features and advantages may be more clearly understood from the following detailed description considered together with the accompanying drawings, in which:

Fig. 1 is a perspective view of the air-home tow target apparatus;

Fig. 2 is a longitudinal sectional view with parts being broken away and parts in section illustrating a preferred embodiment of the invention;

Fig. 3 is a longitudinal sectional view of the towing apparatus similar to Fig. 2 but at right angles thereto;

Fig. 4 is a front, end view of the turbine wheel and air inlet section of the tow target system with the air inlet. portion omitted;

Fig. 5 is an end view of the Windlass and turbine wheel arrangement;

Fig. 6 is a fragmentary side view in detail of the level wind mechanism;

Fig. 7 is a fragmentary end view of the level wind mechanism;

Fig. 8 is a fragmentary, detailed view in section of the brake mechanism; and

Fig. 9 is an end view of the centrifugal brake mechanism.

With reference to the drawings, there is shown in Figs. 1, 2 and 3 a towing apparatus 10 in which a streamlined pod or shell 11 constitutes the outer framework or boils-- ing enclosing a venturi or air inlet section 12 with valve means 14 including two clamshell type air inlet doors 15 defining the nose portion of the pod for controlling theflow of air into the venturi section. A Windlass drive or cable reeling means is comprised broadly of an air driven turbine wheel or blade unit 17 disposed in the throat of" the venturi 12 with a Windlass drive shaft 18 in direct driven engagement with the turbine Wheel for rotation of a Windlass or reel unit 19 which is inclosed in the body 7 of the pod.

t 24 The launching and recovery a gm yi fi i lfl ltlt'fit means 23 are positioned on the Windlass drive shaft to control both the Windlass and turbine wheel rotation.

Forming the rearward end portion of the tow target system 10 is a launching and recovery assembly 25 for a streamlined, shaped tow target such as that shown at a cylindrical, vented frame or shell 26 forming the rearward end compartment of the streamlined pod for enclosing a target holder unit 28 which is made up of target receiving means 29 and resilient buffer means 30 for launching the target.

The main body portion or framework of the pod 11 is formed of an elongate cylinder preferably of steel and aluminum composition and is provided with suitable shackles 32 for attachment to the underside of a high speed aircraft, such as, to the bomb pylons with the longitudinal axes of the cylindrical pod parallel to the fuselage of the aircraft. In addition to the vented frame section for the target launcher, the main body portion of the pod is also provided with cutaway sections as at 33 behind the turbine drive portion for exhausting the air from the venturi passage.

The venturi 12 which serves as the air inlet means for the turbine forms the inner surface of the forward portion of the pod and is rearwardly convergent from the entrance end thereof into a throat section 34 then is rearwardly divergent so as to terminate adjacent the cutaway or vented sections 33.

To regulate the how of air through the venturi for actuating the turbine wheel, the clarnshell shaped air inlet door members 15 are attached to the forward end portion of the pod. As shown, the inner facing edges of each door pivot at two attachment points 36 on the pod so that the doors are disposed in mating, facing relation and, when closed, will combine to form a streamlined nose portion for the pod. The inner surface of each complementary door member is leveled slightly at 15a so that, in the fully open position, the doors form a convergent extension of the venturi passage and provide a smooth surface for the increased flow of air through the venturi.

The doors are synchronously actuated in opening and closing by rods 33 which are driven by electrical control means 40 including a worm shaft 41 extending from an electric motor 42 and gear box 43 located between the venturi surface and outer pod surface. Operation of the door members can then be accomplished, for example, by actuating an electrical switch in the towing aircraft which is electrically connected to the drive motor 42 to an open, closed or off setting. By actuation of the switch to the open setting the clamshell doors are selectively controlled to move from the closed position to the fully open position in a predetermined time interval. If it is desired to stop the doors at any intermediate position, the electrical switch is returned to the off setting. Electrical power for actuation of the motor is derived by connection of the motor into a pylon circuitry system.

In operating the Windlass drive means, rotation of the Windlass unit for winding the cable towline 20 is controlled by the delivery of air through the venturi 12 for actuation of the turbine wheel 17. For this purpose, the turbine wheel 17 is disposed at the rearward end of the venturi throat region and at right angles thereto so as to traverse the flow of air through the venturi.

The turbine wheel is constructed and mounted to initiate the reel in operation to wind or unwind a predetermined number of feet of extended cable 20 together with the shaped tow target 24 without the necessity of reduction gears which may present a maintenance problem and also decrease the ultimate amount of power available for target operation. The high performance turbine wheel 17 accordingly consists of eight turbine blades 44 inserted into a tapered hub member 45 which is secured to the end of the Windlass drive shaft 18. The blades 44 are preferably set into the hub 45 at substantially a 30 angle to the flow of air through thecenter of the venturi and are rearwardly and outwardly tapered at the ends thereof so as to conform to the angle of the rearward divergent section 35 of the venturi throat region. Furthermore, the front side of each blade is made concave with the opposite side convex, resulting in a high lift airfoil. In this manner the turbine wheel 17 is thus designed and positioned so as to completely traverse the flow of air through 2,892,599 I a r d the venturi 12 with correspondingly close tolerance between the ends of the blades and the venturi in order to derive optimum power from the air stream.

The Windlass drive shaft 18 extends rearwardly from the turbine hub 45 through the Windlass unit 19 and is centrally supported by means of a forward bulkhead 48 which is positioned adjacent to and rearwardly of the air exhaust section and a rear bulkhead 49 positioned in front of the launcher and recovery compartment 25. As shown in Figs. 2 and 3 the Windlass unit is separated from the venturi section by a conical shield 50 which extends outwardly from the turbine hub 45 for attachment to the pod 10 just rearwardly of the cutaway sections forming the exhaust 33. The forward bulkhead 48 includes a circular plate 51 mounted to the conical shield on the windlass drive shaft 18 and divergent wall or strut segments 52 extending outwardly from circular plate 51 for attachment to the pod between the cutaway sections 33. The rear bulkhead 49 is constructed similarly to the forward bulkhead having a circular plate 51 with supporting brackets 53 extending radially outwardly from the circular plate for attachment to the inner surface of the pod 10.

To establish substantially frictionless rotation of the Windlass drive shaft 18, the forward and rear bulkheads 48 and 49 are provided with self-aligning bearings (not shown) disposed between the shaft and the circular plates 51. A steel tube 55 extends between the front and rear drum ends to form a sealed compartment for the Windlass unit. The Windlass drive shaft 18 together with retainer end plates 54 adjacent the forward and rear bulkheads form a reel drum or spool for winding and unwinding of the cable 20. By utilizing the Windlass drive shaft as a reel for the cable towline the power required by the windlass unit for reeling in the cable and target is reduced to more closely conform to the power available from the turbine. Accordingly, the vector forces required for the reel-in operation are correspondingly reduced, and together with the increased power available from the turbine wheel 17, it is possible to eliminate the necessity of reduction gearing or similar construction and to establish aone-to-one ratio between the turbine wheel 17 and Windlass unit 19.

The level wind mechanism 21 is disposed in laterally offset relation with respect to the Windlass shaft 18 as shown in Figs. 3, 4 and 5. A level wind shaft 58 extends between the front and rear bulkheads 48 and 49 parallel to the Windlass drive shaft and is supported for rotation at each end of the shaft by means of suitable self-aligning bearings (not shown) disposed in the front and rear bulkhead shaft receiving openings 59 for the shaft. Extending rearwardly through the rear bulkhead from the Windlass drive shaft and the level wind shaft are a worm 61 and gear shaft 62, respectively. The level wind shaft is driven by the Windlass shaft through gearing 63, the gearing 63 including a transverse shaft 65 having a worm gear 66 to intermesh with the Windlass shaft, and a bevel gear 67 at the opposite end of the transverse shaft to drive a mating bevel gear 68 disposed at the end of the level wind gear shaft 62.

The cable line 20 is uniformly wound and unwound on the Windlass shaft 18 by the utilization of a level wind housing 71 which is disposed on the level wind shaft. The level wind shaft is provided with a spiral groove formation 72 as shown in Fig. 6 which is formed to provide forward and reverse travel of the level wind housing on the shaft. For guiding the level wind housing along the spiral groove formation, a pin member 74 is passed into the housing having a projecting guide piece 75 for slidable travel within the spiral groove formation on the level wind shaft. The cable line 26 is led into and out of the Windlass unit through a cable guide passage 76 which is formed by mutually intersecting rollers 77 disposed at right angles to one another and carried in grooves 76a in the guide passage 76.

To provide additional support for the level wind housing in its travel along the level wind shaft, a level wind' wind housing in its travel along the level wind shaft 58.'

The bar 78 thereby acts to further reduce friction and eliminate any binding action imposed on the level wind mechanism or shaft 58. A support bar receiving opening 79 in the housing contains eight ball bearing members 79a which project from the inner surface of the opening 79 to engage the support bar 78 and to permit substantially frictionless travel of the housing 71 along the support bar 78 and level wind shaft 58.

The cable line is guided rearwardly into the launcher and holder assembly or target compartment from the level line housing by the pulley member 22 projecting from the inner surface of the pod 11 midway between the forward and rear bulkheads 48 and 49. Diposed on the pulley 22 is a suitable cable counter (not shown) for measurement of the extent of cable footage passing over the pulley member 22 for release and retrieval of the target 24.

Due to the high speeds of rotation of the Windlass mechanism and also due to the necessity for stopping and releasing the Windlass mechanism, brake means 23 are disposed on the Windlass shaft 18 just forward of the front face of the front Windlass bulkhead 48 for control of the rotation of the Windlass shaft 18. The brake means 23 are made up of centrifugal brake drum 80 to govern the rotation of the shaft 18 against the possibility of overspeed of the shaft 18 and turbine wheel 17, and a mechanical brake drum 81 for manual release and stopping of the windless mechanism by the pilot. As shown in Figs. 8 and 9, the centrifugal brake drum 80 is disposed adjacent the forward bulkhead 48 with two brake shoe members 82 circumferentially disposed to engage the inner surface of the brake drum 80, each brake shoe having a spring pin arm 83 extending radially outwardly from connection with the windlass shaft 18 to control the outward movement of the brake shoes 82. The springs 83 on each arm are preset to a predetermined r.p.m. value so as to permit contact between the shoes and the brake drum at a predetermined speed of rotation of the Windlass shaft.

The mechanical brake drum 81 is connected directly to the windless shaft 18 in front of the centrifugal brake with the outer periphery of the mechanical brake drum 81 extending over the centrifugal brake drum 80. A brake drum band 85 extends around the mechanical brake drum with the outer end of the band fastened by a linkage arm 86 to a pinned brake handle or lever 87, the brake handle being secured to the front windlass bulkhead 48 above the secured end of the brake band. The inner surface of the brake band 85 is tapered rearwardly and outwardly as shown in Fig. 8 so that forward movement of the handle 87 will move the brake band in a forward direction to contact the oppositely tapered mechanical brake drum 81 to stop the rotating movement of the shaft 18. The lever 87 is actuated through a worm drive shaft 88 by an electric motor and gear box 89 located on the side of the Windlass directly behind the brake actuating lever. The electric motor is operated by the pilot, for example, by means of a suitable two-way electric toggle switch (not shown) electrically connected to the motor. As the switch is depressed to the on position, the electric motor through the gear box and worm drive moves the brake band forward to engage the brake drum. By depressing the switch to the off position the electric motor reverses the action of the gear box and worm drive to the brake to release the brake and shaft for rotation. Electric power for the motor is derived from the pylon circuitry.

The rearward launching and recovery assembly 25 is integrally joined to the main body portion of the pod as shown in Figs. 1, 2 and 3. An annular plate 92 forms a support bulkhead between the windless unit and target compartment for mounting of a pulley 93 to guide the cable 20 into the target compartment for attachment to the target. Suitable cable cutting means (not shown) are also mounted on the plate 92 for emergency release of the target.

The outer shell or frame 26 which forms the outer housing for the target compartment is provided with air vents or cutaway sections spaced circumferentially about the frame or shell. Extending along the length of the pod and target frame are a plurality of longeron supports 94 interconnecting the pod and target frame.

The target holder unit 28 which is mounted within the frame 26 includes the target receiving surfaces made up of pads 29 and resilient or spring biased buffer means 30. The buffer means is comprised of pivot arms 95a attached to one of the longeron supports 94 passing rearwardly fromthe rear Windlass bulkhead. The inner, free-ends of the arms 95a have secured thereto a cup member 9 5, the the cup defining a target receiving surface conforming substantially to the shape of the nose of the target 24. The inner ends of the arms 95a are attached to the cup 95 by cross pins 97 which allow the cup to pivot rearwardly and forwardly to release the target or catch it at the entrance of the aft end of the cylindrical frame 26. The opposite or support ends of the arms 95a have a spring member 98 attached thereto which in turn is secured to a bracket 99 for one of the pads 29. The spring biased arms arid cup member thereby together form the :bufier means operating as a connection and support point for the target 24 as it enters the frame and upon release of the cable 20, acts as a launcher to push the target 24 out of the frame.

To cooperate with the buffer means to hold the target in position within the frame, a ring surface or flexible rim is positioned at the aft, entry end of the frame to support the target. Preferably the bevelled pads 29 are utilized for the purpose. The pads 29 are spaced about the aft, entry end of the frame by means of the brackets 99 which extend inwardly from attachment to the longeron supports 94 at the aft end. The bevelled pads 29 are made flexible, yet are rigidly positioned at the aft end to taper inwardly toward the cup member 95; the pads are also spaced so that in combination they conform to the size and shape of the target 24 when the target nose is engaging the cup member 95 in the forward, biased position.

' The cup member 95 is further provided with a cable guide opening 101 extending therethrough to receive the cable line for connection to the tow target 24. The cable line 20 is thus guided into the target compartment at the most effective point so that control of the cable and target will also control the movement of the buffer system.

In controlling the operation of the air-borne tow target apparatus, the only pilot control means that are necessary are for the air inlet doors 15 and the mechanical brake system 23. The streamlined pod is attached to the aircraft with the tow target supported in the rearward compartment in stowed position as shown in Fig. 1. During flight, when it is desired to effect the withdrawal of the tow target 24, the air inlet doors 15 remain in a closed, streamlined position, and the me.- chanical brake 85 is released. The air stream entering the vented frame 26 together with the spring biased cup member will then cooperate to expel the tow target out of the target holder unit. The tow target is released rearwardly of the towing aircraft a predetermined number of feet as gauged by the cable counter. When the desired towing distance for the tow target is reached the mechanical brake can again -be applied to stop the rotation of the Windlass 57 and further withdrawal of the cable line. In the case of overspeed of the windlass 57 in releasing the target 24 of course the con trifugal brake 80 will operate to govern the speed of rotation. Upon the termination of towing operations, the target 24 is rapidly recovered into the stowed position by releasing the mechanical brake 2.3 and opening the air inlet doors 15 to the fully opened position to actuate the air driven turbine 44.

Target recovery can be rapidly made due to the oneto-one ratio established between the turbine wheel 14 and Windlass mechanism 57 together with the increased power made available for Windlass operation. This is accomplished by utilizing the air inlet doors 15 as extension surfaces of the convergent venturi entrance along with the lightweight, frictionless arrangement of the Windlass mechanism itself. The spring biased cup member 95 and vented frame 26 also cooperate during the final recovery stage of the target, since the cup member 95 is rearwardly biased to cushion the entry of the target 24 into the compartment and the vented portions 90 on the frame permit the flow of air into the holder unit to prevent burbling of the air stream aft of the target compartment. In this way, a relatively uniform flow area free from turbulence is maintained at the point of entry of the target 24 into the frame. The entry of air through the holder unit also reduces the drag of the entire tow target system to a minimum.

From the foregoing description, it will be readily seen that application of the turbine and Windlass mechanism may be made to various types of target systems with the utilization of different types and shapes of target holder systems. Conversely, of course, the target launcher and recovery assembly is adaptabie to other types of tow target devices.

The entire integrated, high performance tow target systern device, combined and inclosed in a single, streamlined unit accordingly provides a complete tow target system, light in weight, simple in operation with an extremely low maintenance factor. The entire system may be attached to an aircraft at a single attachment area thereby decreasing drag and enhancing the possibility of the towing aircraft operating at its peak performance value.

While a preferred embodiment of the present invention is hereinbefore set forth it is to be understood that the present invention is not to be limited to the exact con struction illustrated and described and that various modifications may be made within the scope of the appended claims.

What is claimed is:

1. In an air-borne towing apparatus of the character described, the combination comprising: an outer housing having a forward end, means enclosed within said housing for winding and unwinding a tow line, means within the housing for guiding and controlling the winding and unwinding of a cable towline, air actuated drive means disposed within the forward end of said housing for driving said cable winding and unwinding means, and valve means to regulate the mass flow of air into the forward end of said housing for actuating said drive means, said valve means constituting a segmental, streamlined nose portion comprising a pair of semiconical forwardly extending doors pivoted at their rear ends to the forward end of said housing at diametrically opposite sides thereof and including means to simultaneously move said doors between an open, air receiving position and a closed, streamlined position.

2. In an air-borne towing apparatus of the character described for the release and recovery of a tow cable and an attached tow target, the combination comprising: a housing having a forward end, a Windlass within said housing for winding and unwinding said cable, means for guiding and controlling the winding and unwinding of said cable on said Windlass, air inlet means at the forward end of said housing, an impeller member disposed within said housing actuated by the air flow through said air inlet means for rotating said Windlass, and valve means over the forward end of said housing to control the flow of air through said air inlet means, said valve means comprising streamlined door members pivotally attached to the front end of said housing to form a forwardly projecting streamlined nose portion thereof when closed and electrical control means to control the opening and closing of said door members.

3. in a towing device substantially as described, the combination comprising: an outer pod member having an air entrance end and disposed for attachment to a tow aircraft; Windlass means disposed within said pod memher for winding and unwinding a tow line for a streamlined tow target, means for guiding and controlling the winding and unwinding of said towline; means for rotating said Windlass for winding of said tow line comprising a venturi air inlet disposed at the entrance end of said outer pod member, an impeller located in the throat region of said venturi to traverse the flow of air therethrough and rotatable by the flow of air through said throat region, a common drive shaft for said impeller and said Windlass for rotating said Windlass for the winding of said towline at a one-to-one ratio upon rotation of said impeller by the air passing through said throat region; forwardly projecting air inlet valve means at the forward end of said outer pod member for controlling the mass flow of air into and through said venturi comprising a pair of complementary forwardly projecting streamlined door members pivotally connected at their rear ends to the entrance end of said outer pod member at opposite sides thereof, and means for simultaneously moving said door members between a forwardly projecting closed position defining a streamlined nose for said outer pod member and an outwardly and forwardly projection position forming scoop means to gather and direct air into said venturi passage for actuating said impeller when said towing device is attached to a tow aircraft which is in flight.

4. A towing device according to claim 3, in which said door members are so constructed and arranged as to swing to an open position defining a divergent forward extension of said venturi passage for increasing the flow of air therethrough into said venturi.

5. An integrated tow target system for a streamlined tow target and the like comprising: an elongated unitary housing attachable as a unit to the underside of an aircraft and having a longitudinal axis and forward end, forwardly projecting inwardly tapering complementary air inlet doors pivotally connected at their rear ends to the forward end of said housing defining a streamlined openable nose portion of said housing when said doors are closed, means connected between said housing and said doors for simultaneously actuating said doors between said streamlined closed position and a fully open position, said housing having an annular concentric venturi passage therein surrounding said longitudinal axis and having an annular air intake portion in the forward end of the housing tapering rearwardly to form an annular throat portion, an outwardly and rearwardly extending air discharge passage formed in the housing inclining outwardly from said throat portion through the exterior longitudinal side of said housing, said doors having inner surfaces forming forwardly diverging extensions from the forward end of the venturi air inlet when said doors are fully open for inducing increased flow of air into and through said venturi inlet portion when said housing is attached to an aircraft which is in flight, a turbine wheel traversing the throat of said venturi, a Windlass shaft journalled within said housing and extending rearwardly from said turbine wheel in direct drive connection with the turbine wheel, a tow cable Windlass fixed on said Windlass shaft and extending longitudinally within said housing rearwardly of said turbine wheel, a tow cable wound on said Windlass having a free end extending through the rear end of said housing, a streamlined tow target attached to the free end of said tow cable, level wind means and brake means within said housing for controlling the level winding and unwinding of the tow cable, and target launching and holding means carried wholly within the rear end portion of said housing for receiving the tow cable therethrough when attached to the tow target, said launching means being arranged to launch a tow target attached to said tow cable rearwardly from the rear end of said housing, and said holding means being arranged to receive and hold a tow target when attached to the tow cable and drawn into the rear end of said housing by rotation of said Windlass by said turbine wheel in winding up the tow cable thereon.

6. In an air vehicle towing apparatus, the combination of a unitary streamlined pod attachable to the underside of a towing airplane having a streamlined nose, a body portion, and a rearwardly disposed tow target storage and launching compartment, said body portion having an annular rearwardly extending venturi passage at the forward end thereof, an air driven turbine wheel and Windlass inclosed within said body portion, a turbine wheel shaft for said turbine wheel journalled in said body portion with said turbine wheel fixed on said shaft and disposed in the throat of said venturi to traverse the flow of air therethrough, said inclosed Windlass disposed in alignment with the turbine wheel axis in direct drive engagement with said turbine wheel shaft, said Windlass including a tow cable wound thereon and level wind mechanism for guiding said tow cable, a centrifugal brake for said Windlass in said body portion to govern the speed of rotation of said Windlass, a mechanical brake in said body portion for said Windlass including remote control means for said mechanical brake to manually control the rotation of said Windlass, and means for guiding said tow cable from said Windlass through said rearwardly disposed compartment for attachment thereto of a streamlined tow target, complementary forwardly projecting clam shell door segments pivotally attached at opposite sides of their rear ends to the forward end of said body portion to form said streamlined forwardly projecting nose portion when said door segments are closed, electrical control means between the body portion and both of said door segments to move said door segments simultaneously to the closed, streamlined position and to a fully open air intake position, said door having inner surfaces arranged to form a forwardly divergent extension of said venturi passage at the inlet of said venturi passage in their open position for increasing the flow of air into said venturi when said towing apparatus is attached to the underside of a towing airplane in flight, and vehicle launching and holding means in the vehicle storage and launching compartment of the pod for effecting release and retrieval of a streamlined tow target when attached to said tow cable.

7. In an air-borne tow target apparatus for the controlled release and recovery of a tow cable and attached streamlined tow target, the combination comprising: a cylindrical pod having a forward end and a rearward target compartment for the launching and recovery of said tow target; a Windlass unit including a Windlass enclosed within the body of said pod including a Windlass drive shaft disposed parallel to the longitudinal axis of said pod for the reeling in and out of a tow cable thereon, means for guiding said cable between said Windlass shaft and said rearward compartment, and brake means for controlling the release and speed of rotation of said cable; a venturi shaped air inlet enclosed Within the forward end of said pod, a turbine wheel disposed in the throat region of said venturi so as to traverse the flow of air therethrough, said Windlass shaft being connected to said turbine wheel for rotation by said turbine at a one-to-one ratio; and a pair of clamshell shaped, complementary door members pivotally attached at the inner, facing edges thereof to the forward end of said pod and inclining forwardly and inwardly to form a streamlined forward nose extension for said pod when closed, means to swing said door members between a closed streamlined position and an open position, said door members having the inner surfaces when the door members are in the open position defining a divergent forward extension of said venturi to cause the increased flow of air through said venturi.

References Cited in the file of this patent UNITED STATES PATENTS 2,735,264 Iewett Feb. 21, 1956 2,760,777 Cotton Aug. 28, 1956 2,778,584 Wilson Jan. 22, 1957 2,813,719 Hopper Nov. 19, 1957 

